What is CAD?

Artec 3D scanning captures with sufficient accuracy for complex CAD design

Computer-aided design is such a cutting-edge and prevalent product iteration tool, you’d be forgiven for thinking it was invented recently. On the contrary, Dr. Patrick Hanratty laid its foundations with ‘PRONTO,’ the first commercial numerical control system, way back in 1957.

Six years later, Ivan Sutherland took things a step further with SketchPad, a breakthrough machine that allowed for the first human-computer interactions. While Sutherland’s device only supported basic elements like arcs and line segments, it allowed mechanical designs to be drawn on-screen like never before, making it a precursor to future CAD systems.

Not long after, firms began to launch their own CAD programs. With code supplied by Hanratty, McDonnell Douglas introduced a computer software for part layout and geometry in 1967. While the company has since disappeared, merging with Boeing, its MicroGDS CAD platform has proven so successful it continues to be used today.

Over the decades, CAD has remained a hot topic of research. At Computervision, one of the industry’s main early players, Dr. Ken Versprille developed NURBS (non-uniform rational b-splines) in 1975. Now a 3D modeling mainstay, the feature allows for the creation of complex CAD models with curved surfaces.

Since then, advances like parametric modeling, first commercialized by CREO, have changed the way CAD is utilized – allowing models to be tweaked based on preset parameters. If some features need modifying, for instance, simply adjusting a model’s parameters in initial sketches is enough to recalculate and reshape it entirely.

More recently, CAD technology has also continued converging with 3D printing and 3D scanning, and new features are constantly bringing the technologies closer together.

Broadly, the different types of CAD can be broken down into solid, wireframe, and surface modeling. Though other approaches warrant mentioning, most fit into these three categories.

Solid modeling is ideal for assembling primitive shapes like lines, arches, spheres, and cubes into complex models, while maintaining a calculable object volume. This allows designers to constantly validate builds and ensure they can be viably manufactured.

By contrast, wireframe modeling only depicts a model’s edge and corner surfaces, enabling them to be crafted with greater subtlety. On a technical level, this is achieved by representing models as vertices linked by ‘faces,’ which can be modified to change their position and create curved surfaces on an object’s exterior.

Advances in CAD technology continue to remove design limitations

Lastly, with surface modeling, users can build models via a series of guiding lines or control points. These are then connected to form surfaces by CAD platforms, which calculate the smoothest way of doing so. As you can imagine, this method’s seamless, flowing surface focus makes it ideal for automotive and aerospace modeling – where airflow is key.

Other approaches, such as generative design, are threatening to take human error out of the equation altogether. Designers can now charge AI with overcoming design issues, whether these relate to weight, cost, or performance, and it will come up with a solution. All they need to do is enter the parameters they’re working to and algorithms do the rest.

AI isn’t the only advanced technology making waves in CAD. With 3D scanning, it’s now possible to not just automate design steps but eliminate some altogether by digitizing existing products and using them as a basis for future physical prototypes.

So, that’s how 3D scanning fits into 3D CAD design. But what happens once you’ve captured the data you need? Can you just start editing scans on CAD software?

Well, not immediately. First, scans need to be transformed into solid 3D models, and this workflow continues to get easier thanks to advances in the ‘scan-to-CAD’ programs that serve as a bridge between mesh and model.

Getting from scan to CAD takes a few steps, but the results speak for themselves

A great platform on which to start this workflow, Artec Studio streamlines scan data capture and processing, simplifying some steps to a single click. Geometry and texture tracking algorithms ensure engineers capture parts in high detail, while the platform’s growing Boolean operations toolkit can be used to enhance meshes e.g. by thickening surfaces likely to break.

Artec Studio gives you everything needed to prepare your mesh and carry out essential reverse engineering tasks. On the platform, you can move & offset faces to make modifications, add polish with chamfer and fillet tools, and create new shapes by adding, subtracting, or intersecting primitives with other models, all in one place.

Programs like Geomagic for SOLIDWORKS expedite the process of turning this highly polished mesh into a CAD model. Plugging directly into your SOLIDWORKS workspace, the add-on gives you the feature extraction tools needed to create solid, editable models from scan data. If you want to quickly, easily, and accurately fix or edit an existing design in a familiar interface, the program represents an ideal Artec Studio companion.

For intensive reverse engineering, leading software Geomagic Design X comes with a more comprehensive scan-to-CAD toolset. With exact surfacing, it’s possible to reconstruct complex freeform shapes, then deploy the platform’s patching feature to instantly add surface bodies, which closely follow object contours and curves.

Geomagic develops some of the industry’s leading scan-to-CAD platforms

When it comes to 2D & 3D sketching, Design X offers the perfect basis for rapid scan-based engineering. Auto Sketch can be used to accelerate geometry extraction, and configured to automatically fit shapes to polyline entities, in a way that meets desired parameters. Other tools like Loft and Sweep also make it easy to blend sections into seamless surfaces.

More broadly, there’s now a significant overlap between CAD and scan-to-CAD programs, with many traditional design platforms integrating 3D scan-friendly functionalities. Let’s take a look at some of the most popular, what they offer, and where they’re best used.

Product design

Even though iteration is necessary to ensuring product quality across a range of industries, many of these applications share a common thread: a reliance on CAD. In some areas, initial designs may still be outlined via traditional drafting, but the long, drawn-out iterative sketching processes that delayed the product launches of the past, have largely been shelved.

CAD design is even taking over in automotive – where sketching has traditionally flourished

Beyond prototyping speed, the introduction of CAD has helped overcome issues around the misinterpretation and sharing of scaled diagrams. Design digitization and the ubiquity of CAD have also unlocked previously unthinkable levels of automation and collaboration.

The arrival of CAD hasn’t just changed the way products are designed either, it has opened up entirely new avenues. Before, previewing an early design would require a mock-up to be made and shipped. Now, businesses like luxury furnishings firm Sherrill Furniture are able to digitize furniture with 3D scanning in minutes, and use this data to create dozens of CGI lounge items for customization and 3D visualization each week.

This has been made possible by the lightning-fast 35 million pts/s Artec Leo. Featuring click-to-scan functionality and sub-millimeter 3D scanning capabilities, Leo makes capturing intricate, texture-rich items like furniture in crowded showrooms quick and easy – it also unlocks applications elsewhere, as we’ll explore next.

Engineering

CAE is where CAD really comes in handy for mechanical engineers – as a means of analyzing the performance of mechanical parts and assemblies before they go into production. Similarly to product prototyping, this saves manufacturers from having to make wasteful mock-ups as they can simulate how they’ll work instead.

However, engineering requires a completely different simulation toolset. Autodesk has recognized this with Inventor: a platform that pairs hand-drafting essentials with static and modal stress analysis tools for testing if products can withstand set loads.

Elsewhere, Siemens offers the Simcenter FLOEFD CAD-embedded computational fluid dynamics (CFD) software. With CFD simulation, it’s possible to predict how fluids like air and water will flow around a model – and by extension – how they can be channeled to make it more aerodynamic. This is particularly important in areas like competitive cycling, where minimizing air resistance is key to finishing first.

Using data captured with Leo and the ultra-precise Artec Space Spider, UK sim firm Vorteq has taken this approach to the next level, building the world’s fastest racing bike. While Leo’s speed and wireless portability accelerated capture for comparative analysis, it was the sheer detail picked up by the 0.1mm-resolution Space Spider that allowed the forces going through the bike’s frame to be modeled using CFD.

With other functionalities like multibody dynamic analysis (for examining how connected bodies behave) also making their way into many platforms, detailed engineering clearly remains one of the most exciting areas in CAD design.

Automotive

In automotive, the artistry behind hand-drawn car designs remains very much alive, only CAD modeling has brought it into the 21^st century. The process still tends to begin with sketches, but engineers have begun turning these into virtual designs by digitally drafting them on CAD platforms and using the resulting models to create life-sized prototypes for testing.

Many tuning firms capture existing models, then digitally design desired upgrades

Digitizing conceptual designs adds precision to the process, enabling users to ensure they fit and operate as intended. It also yields models that can be fed into simulations to identify how a part or assembly will perform under load. Whether this be an aerodynamic or physical load, the results can be used to analyze design safety and performance.

With 3D scanning, it’s now possible to reverse engineer such models from real-world objects with such speed and accuracy, they can be used for product iteration. In the past, the SNAG Racing Rallye team has managed to use the highly flexible Artec Eva – a time-tested solution for digitizing medium-sized textured parts – for this very purpose.

Switching from paper modeling to 3D scanning for designing rally car upgrades has allowed them to make strength, speed, and maneuverability gains, while achieving lower production costs and lead times.

Architecture

While CAD is utilized to design architecture of all shapes and sizes, this is usually achieved with dedicated software, rather than mainstream ones. As is the case with product sketching, digitizing building design and project management has made it possible to iteratively make changes (in this case client-requested ones), without civil engineers having to start afresh.

More often called building information modeling (BIM) than CAD, the process also allows architects to preview how building plans will look once borne out. Popular software packages like ArchiCAD even enable users to generate photo-realistic visuals well before a shovel breaks ground, to help interior designers, and for marketing properties in advance.

Long-range 3D scanning allows you to digitize facilities and drive on-site efficiency

With there being so many stakeholders in construction, BIM is an important site planning tool as well. Essentially, BIM modeling has seven collaboration levels, with the first being 2D drawings, and the last seeing these turned into a 3D model and shared with all involved. As it facilitates efficient site planning and costing, the latter is seen as the cutting edge.

Dental & medical

CAD is also thriving in dental, although it’s more often used for custom implant manufacturing than purely as a design tool. Dental CAM sees teeth 3D modeled, either via impressions or scans of patients’ mouths, and used as a basis for producing restorations.

Before dental CAD/CAM properly took hold in the 1980s, creating patient-specific crowns, implants, or dentures, would involve several trips to the dentist, after which molds would be sent for production. Now, dentists can manufacture in-house, using 3D scanning to capture smiles with enough precision to develop perfectly fitting dental implants.

One such practice, the Center for Implant Dentistry, has uncovered a way of combining super accurate full-color Space Spider scans with intraoral ones, to create incredibly realistic teeth models. Not only has this accelerated its implant design process, but allowed patients to preview their new smiles – and the clinic’s approval rates have soared ever since.

Unsurprisingly, given how easy it is to turn CAD output into STL files, 3D printing is also becoming a popular alternative to outsourcing, and there’s much potential in pairing the two technologies to achieve higher-accuracy dental results.

3D printing is starting to take off in healthcare too, where efforts continue to integrate CAD into the standard ‘DICOM’ clinical data format. It’s anticipated that CAD’s further adoption there will make it easier to customize casts and prosthetics, as well as drive surgical planning and drug design forward through biological modeling.